The mobilization of young voters: Evidence from a field experiment

EPSA 2025, Madrid

Frederik
Thieme
frederik.thieme@hu-berlin.de

Humboldt-Universität zu Berlin

Heike
Klüver

Humboldt-Universität zu Berlin

June 26, 2025

Motivation 📬

Source: The Guardian (April 28, 2025)

Source: WAZ (May 30, 2024)

Overview

  • ❓ Question: Can traditional campaign tools still mobilize young voters in the digital age?
  • 💡 Idea:
    • Status-Quo: cost-intense practice of mailed letters in campaigns, promise of precise targeting
    • Argument: media habits of young generations have changed, re-evaluation of GOTV literature necessary
  • ️⚙️ Data & Method:
    • field experiment targeting first-voters with German Green party, European Elections 2024
    • 37,000 letters, randomized at ZIP-code level + post-election survey (N = 1,400)
  • 📊 Results:
    • no effects on turnout or party vote choice in aggregate & survey analysis
    • little effect heterogeneity and low recall

GOTV past and present

Previous literature 📚

However …

  • heightened priority of digital media in modern campaigns
  • continued promise & use of mail campaigns

Field Experiment

  • cooperation with the German Greens in the city-state of Berlin
  • targeting first-voters in the European Elections 2024 (born 2004-08)
  • 37,000 letters, randomized at the ZIP-code level
  • post-election survey with random selection from both treatment & control

Treatment

  • personalized letter by local candidate
  • strong party branding
  • text tailored to speak to issues relevant to young people

Results: Aggregate 📊

Results: Survey 📊

Results: Survey 📊

  • overall null effects on turnout and party vote share
  • no movement on proposed mechanisms
    • e.g. relevance EU politics, information level, political efficacy
  • effect heterogeneity (causal forest)
    • overall low heterogeneity in line with null-effects
    • some movement along political efficacy, trust, climate importance

Limiting factors 📊

  • less than half of treated respondents recalled receiving a letter
  • effects remain null in this sample
  • mostly agree they were not interested in the letter

Takeaway 🥡

  • no effect of campaign letters on turnout or vote choice of first voters
  • although personalized and potential to “cut through the noise”
  • ineffective albeit costly strategy, at least when targeting first voters

Outlook 🔭

  • re-evaluation of field-experimental evidence from GOTV campaigns necessary
  • campaigns need to update strategies to reach young cohorts

Thank you for your attention.

Questions or feedback? Hit me up:

Literature 📚

Green, Donald P., and Alan S. Gerber. 2019. Get Out the Vote: How to Increase Voter Turnout. Fourth edition. Washington, D.C: Brookings Institution Press.
Malhotra, Neil, Melissa R. Michelson, Todd Rogers, and Ali Adam Valenzuela. 2011. “Text Messages as Mobilization Tools: The Conditional Effect of Habitual Voting and Election Salience.” American Politics Research 39 (4): 664–81. https://doi.org/10.1177/1532673X11398438.
Nickerson, David W. 2006. “Volunteer Phone Calls Can Increase Turnout: Evidence from Eight Field Experiments.” American Politics Research 34 (3): 271–92. https://doi.org/10.1177/1532673X05275923.